^ Most of the oil/coating products will darken the leather. It's all up to your preference and what condition you wear it in.... Some people beat the shit outta their CDB's without any oil/coating and it has a different type of look that I really like. Lent my buddy my Montana Pitch Blend for his Beeswax CDB's and he liked the darkened look.
I think this worn pair looks pretty nice
Treated with obenauf which darkens the leather (not mine)